Aqueous Fe-I₂ rechargeable batteries are highly desirable for large-scale energy storage because of their intrinsic safety, cost effective, and wide abundance of iron and iodine. However, their development suffers from Fe dendrite growth and severe shuttle effect during cycling. Herein, we demonstrate a high-performance Fe-I₂ rechargeable battery using metal iron as anode, iodine/hierarchically porous carbon composite as cathode and an eco-friendly aqueous electrolyte. The anode modified with ascorbic acid effectively suppresses the formation of iron dendrite, while the cathode doped with nitrogen greatly reduces the shuttle of iodine species. The battery operates a reversible redox reaction of FeI₂/I₂ pair with fast kinetics. A capacity ∼190 mAh g^-1 at current densities up to 5000 mA g^-1 and excellent cycle stability of 100% after 550 cycles at 2000 mA g^-1 are obtained. The battery achieves superior power density of ∼1300 W kg^-1 at 120 Wh kg^-1 and high energy density of 130 Wh kg^-1 at 356 W kg^-1. Our study shows great promise for high-performance rechargeable batteries with low-cost, eco-friendliness and high safety.

Fe-I ₂水性充电电池由于其本质安全性，成本效益以及大量的铁和碘而非常需要用于大规模储能。然而，它们的发展遭受铁枝晶生长和在循环期间严重的穿梭效应的困扰。本文中，我们演示了一种高性能的Fe-I ₂可充电电池，该电池使用金属铁作为阳极，使用碘/多级多孔碳复合材料作为阴极，并使用环保的水性电解质。用抗坏血酸修饰的阳极有效地抑制了铁枝晶的形成，而掺有氮的阴极则大大减少了碘的迁移。电池进行FeI ₂ / I ₂的可逆氧化还原反应与快速动力学配对。在电流密度高达5000 mA g ^-1时，容量约为190 mAh g ^-1，在2000 mA g ^-1下经过550次循环后，具有100％的出色循环稳定性。该电池在120 Wh kg ^-1时可达到约1300 W kg ^-1的出色功率密度，而在356 W kg ^-1时可达到130 Wh kg ^-1的高能量密度。我们的研究表明，低成本，环保，高安全性的高性能可充电电池前景广阔。